Energy used by the bees Apis mellifera L. and Apis cerana F. were studied in relation to various rapeseed mustard (Brassica campestris var toria) and fruit crops (Litchi chinensis Sonn. and Citrus sinensis L.). Laboratory measurements of physiological energetics were compared with field observations on time budget and energy intake to infer daily energy budget balance. The energy balance varied from one day to another and from crop to crop, but in general the foraging profitability per bee was in the order: Citrus sinensis> Litchi chinensis> Brassica campestris var toria. Citrus sinensis appears to be competitively superior as a forage crop over Litchi chinensis and Brassica campestris var toria.